摘要
从ＨｅＬａ细胞提取的ＤＮＡ经ＤＮａｓｅⅠ酶解后，发现有两种抗酶组分（Ｂ和Ｃ）。凝胶电泳结果显示组分Ｂ的分子大小要超过２００００ｂｐ，而组分Ｃ的分子大小相当于４０～５０ｂｐ。这两种组分在原子力显微镜下的形态都明显不同于标准的双链ＤＮＡ，其中组分Ｂ与以前观察到的λ－ＤＮＡ变异结构较为相似，组分Ｃ则未见报道，根据其分子的表观宽度和高度推测可能为四链结构。此外，荧光实验还表明这两种组分可与ＥＢ相互作用。
A DNA sample extracted from HeLa cells was digested by DNaseⅠ and found to contain two enzyme resistant species (termed as B and C). Results from gel electrophoresis showed that the fragment sizes of species B were more than 20000 bp and that of species C were between 40-50bp. All these two species were different from the standard duplex DNA in the image of atomic force microscopy, among which species B exhibited characteristics similar to a reported unusual form of λ DNA. Species C has not been reported and was assumed to be quadruplex according to its apparent width and height. In addition,the fluorescence experiments showed that they can also interact with EB and increase its fluorescence intensity.
基金
中国科学院"九五"重大课题
